Method, system and authentication centre for authenticating in end-to-end communications based on a mobile network

ABSTRACT

The invention discloses a method for authenticating in end-to-end communications based on a mobile network, applied to a system including a first service entity requesting a service, a second service entity providing the service and an entity authentication centre, EAC; respectively performing a mutual authentication between the first service entity and the EAC and that between the second service entity and the EAC according to the negotiated authentication mode; if the first service entity requests the second service entity to provide the service, the EAC providing authentication inquiring for the first service entity and the second service entity according to the negotiated authentication mode, and generating a shared derived key according to the negotiated authentication mode; and the first service entity and the second service entity authenticating each other according to the shared derived key and the negotiated authentication mode, and generating a session key for protecting the service.

This application is a continuation of International Patent ApplicationNo. PCT/CN2006/003601, filed Dec. 26, 2006, which claims priority toChinese Patent Application No. 200610033377.2, filed Jan. 24, 2006,Chinese Patent Application No. 200610074902.5, filed Apr. 4, 2006, andChinese Patent Application No. 200610079252.3, filed Apr. 20, 2006, allof which are hereby incorporated by reference.

FIELD OF THE INVENTION

The present relates to network communication service techniques, andmore particularly, to a method, a system and an authentication centrefor authenticating in end-to-end communications based on a mobilenetwork.

BACKGROUND OF THE INVENTION

At present, when providing a service to a mobile subscriber, a majorityof application servers first establish with the mobile subscriber amutual trust relationship, such as that between the mobile subscriberand an authentication proxy, that between the mobile subscriber and aPublic Key Infrastructure (PKI) certificate organization, that betweenthe mobile subscriber and the content providing server, and the like.Generally, such trust relationship is established during thebidirectional authentication procedure between the mobile subscriber andthe application server.

In the 3G radio communication standards, Generic AuthenticationArchitecture (GAA) is a general architecture used by various applicationservice entities to verify subscriber identities and can checkapplication service subscribers and verify the subscriber identities.The above application service can be a multicast/broadcast service, auser certificate service, a service for providing instant information,or a proxy service.

FIG. 1 is a schematic diagram illustrating the architecture of the GAAwhich generally includes a subscriber 101, a Bootstrapping ServerFunction (BSF) 102 performing initial check and verification ofsubscriber identities, a Home Subscriber Server (HSS) 103 and a NetworkApplication Function (NAF) 104. BSF 102 serves to perform mutualidentity verification with subscriber 101 and generate a shared key forBSF 102 and subscriber 101. HSS 103 stores a Profile for describingsubscriber information and has the function of generating authenticationinformation.

When desiring to use a service, the subscriber communicates with the BSFdirectly for mutual authentication if the service needs a mutualauthentication procedure with the BSF. Otherwise, the subscriber firstcontacts a NAF corresponding to the service, and if the NAF uses the GAAand the subscriber requesting the service has not communicated with theBSF for the mutual authentication procedure, the NAF notifies thesubscriber requesting the service to perform the identity verificationwith the BSF.

Upon successful mutual authentication, the subscriber and the BSFauthenticate each other's identity and generate a shared key, Ks.Further, the BSF defines a lifetime for the Ks to facilitate its update.Later, the BSF allocates a Bootstrapping Transaction Identifier (B-TID)for the subscriber and transfer the B-TID with the lifetime for the Ksto the user equipment (UE), wherein the B-TID is associated with the Ks.The shared key, Ks, which is used as a root key, will not leave thesubscriber's UE and BSF. When the subscriber communicates with the NAF,a key derived from the Ks, Ks_NAF, is used to protect the communication.

The disadvantages of the GAA are: 1. only one authentication mechanism(i.e., the AKA authentication mechanism) being supported in theauthentication between the subscriber and the BSF; 2. the authenticationmechanism not providing the authentication between the BSF and NAF,which may result in stealing of secret information of the subscriber byattackers counterfeiting the NAF.

In 3GPP2, there is also a GAA, referring to FIG. 2. FIG. 2 is a diagramillustrating a GAA in the existing 3GPP2. The GAA in 3GPP2 includes aMobile Node (MN) 201, a Network Application Function (NAF) 202, a BSF203 for performing initial check and verification of subscriberidentities, an HSS 204, a Home Location Register/Authentication Centre(HLR/AC), and an Authentication Authorization Accounting (AAA) server.

If desiring to use the service provided by the NAF, the MN first has toperform the mutual authentication with the BSF. There are three types ofmutual authentication mechanisms (including an AKA authenticationmechanism, a CAVE-based authentication mechanism and an AAA-basedauthentication mechanism) which can be chosen freely according to thesupport condition of the MN and network and the operator's local policy.

However, the GAA in 3GPP2 only supports three authentication mechanisms,which is not applicable for the mutual authentication between oneservice entity and various networks. Furthermore, the authenticationmechanism does not provide the authentication between the BSF and theNAF, which may result in stealing of secret information of thesubscriber by attackers counterfeiting the NAF.

To sum up, the existing GAAs are just applicable within the standardthey belong to and are restricted by the networks and the serviceentities, and thus have some limitations.

SUMMARY OF THE INVENTION

The embodiments according to the present invention provide genericauthentication architecture applicable for different mobile networkstandards so as to establish a mutual trust relationship between variousentities.

The technical solutions in accordance with the embodiments of thepresent invention are as follows:

The embodiments of the invention disclose a method for authenticating inend-to-end communications based on a mobile network, applied to a systemincluding a first service entity requesting a service, a second serviceentity providing the service and an entity authentication centre, EAC,including:

negotiating an authentication mode between the first service entity andthe EAC, wherein the negotiated authentication mode includes: anauthentication mechanism between the first service entity and the EAC,an authentication mechanism between the second service entity and theEAC, a mechanism of authentication inquiring, a mechanism for generatinga derived key, and an authentication mechanism between the first serviceentity and the second service entity;

performing a mutual authentication between the EAC and the first serviceentity according to the authentication mechanism between the firstservice entity and the EAC included in the negotiated authenticationmode, and performing a mutual authentication between the EAC and thesecond service entity according to the authentication mechanism betweenthe second service entity and the EAC included in the negotiatedauthentication mode;

if the first service entity requests the second service entity toprovide the service, the EAC providing authentication inquiring for thefirst service entity and the second service entity according to themechanism of authentication inquiring included in the negotiatedauthentication mode, and generating a shared derived key for protectingthe communication between the first service entity and the secondservice entity according to the mechanism for generating a derived keyincluded in the negotiated authentication mode; and

the first service entity and the second service entity authenticatingeach other according to the shared derived key and the authenticationmechanism between the first service entity and the second service entityincluded in the negotiated authentication mode, and generating a sessionkey for protecting the service.

The embodiments of the invention also disclose a method forauthenticating service entities, applied to a service entity and an EAC,including:

negotiating an authentication mode between the service entity and theEAC, wherein the negotiated authentication mode includes anauthentication mechanism between the service entity and the EAC; andperforming a mutual authentication between the service entity and theEAC according to the authentication mechanism included in the negotiatedauthentication mode.

The embodiments of the invention disclose a method of authenticationinquiring, applied to a system including a first service entityrequesting a service, a second service entity providing the service andan EAC, wherein, a mutual authentication between the first serviceentity and the EAC and that between the second service entity and theEAC are respectively performed, the EAC allocates temporary identitiesrespectively for the first service entity and the second service entityand acquires the shared key materials respectively for protecting thecommunications with the first service entity and the second serviceentity, and with the EAC, the first service entity negotiates anauthentication mode including a mechanism of authentication inquiringand a mechanism for generating a derived key; the method including:

if the first service entity requests the service provided by the secondservice entity, authenticating authorities of the first service entityand the second service entity according to the temporary identities ofthe first service entity and the second service entity according to themechanism of authentication inquiring included in the negotiatedauthentication mode; and calculating a shared derived key for protectingthe communication between the first service entity and the secondservice entity according to the mechanism for generating the derived keyincluded in the negotiated authentication mode, the temporary identitiesof the first service entity and the second service entity, and theshared key material for protecting the communication with the firstservice entity.

The embodiments of the invention disclose a system for authenticating inend-to-end communications based on a mobile network, including a firstservice entity requesting a service, a second service entity providing aservice and an EAC, wherein,

the first service entity is configured to negotiate with the EAC anauthentication mode including at least one mechanism related withauthentication, to perform a mutual authentication between the firstservice sentity and the EAC according to the negotiated authenticationmode, to request a service from the second service entity, and toperform a mutual authentication between the first service entity and thesecond service entity according to the shared derived key for protectingthe communication between the first service entity and the secondservice entity according to the negotiated authentication mode;

the second service entity is configured to authenticate the EACaccording to the negotiated authentication mode, and to perform themutual authentication between the second service entity and the firstservice entity according to the shared derived key for protecting thecommunication between the first service entity and the second serviceentity according to the negotiated authentication mode if the firstservice entity requests the service; and

the EAC is configured to respectively perform the mutual authenticationbetween the EAC and the first service entity and that between EAC andthe second service entity according to the negotiated authenticationmode, and when the first service requests the service, to provide anauthentication inquiring for the first service entity and the secondservice entity according to the negotiated authentication mode and togenerate the shared derived key for protecting the communication betweenthe first service entity and the second service entity.

The embodiments of the invention also disclose a system forauthenticating service entities, including a service entity and an EAC,wherein,

the service entity is configured to negotiate with the EAC anauthentication mode which includes an authentication mechanism betweenthe service entity and the EAC, and to perform a mutual authenticationbetween the service entity and the EAC according to the authenticationmechanism included in the negotiated authentication mode.

The embodiments of the invention further disclose a system ofauthentication inquiring, including a first service entity requesting aservice, a second service entity providing the service and an EAC,wherein,

the first service entity is configured to negotiate with the EAC anauthentication mode which includes a mechanism of authenticationinquiring and a mechanism for generating a derived key; and

the EAC is configured to, when the first service entity requests theservice, authenticate the authorities of the first service entity andthe second service entity according to the mechanism of authenticationinquiring included in the negotiated authentication mode, and togenerate a shared derived key for protecting the communication betweenthe first service entity and the second service entity according to themechanism for generating the derived key included in the negotiatedauthentication mode.

The embodiments of the invention disclose an authentication centre,including:

a first module, configured to negotiate an authentication mode of aservice entity, wherein the authentication mode includes anauthentication mechanism between the service entity and theauthentication centre; and a second module, configured to authenticatethe service entity according to the authentication mechanism included inthe authentication mode negotiated by the first module.

In the above authentication centre, the first module includes: a firstsub-module, configured to inquire subscription data to respectivelyacquire authentication capabilities of the service entity requesting aservice and the service entity providing the service; and a secondsub-module, configured to select an authentication mode according to theauthentication capabilities of the service entity requesting the serviceand the service entity providing the service, the authenticationcapabilities being acquired by the first module.

In the above authentication centre, the authentication mode furtherincludes a mechanism of authentication inquiring and a mechanism forgenerating a derived key, and the authentication centre furtherincludes: a third module, configured to, when the service entityrequests the service, provide authentication inquiring for the serviceentity requesting the service and the service entity providing theservice, and to calculate the shared derived key for protecting thecommunication between the two service entities according to themechanism of authentication inquiring and the mechanism for generatingthe derived key included in the authentication mode negotiated by thefirst module.

In the above authentication centre the second module is configured togenerate shared key materials and temporary identities for the twoservice entities, and the third module is configured to calculate theshared derived key according to the shared key materials and thetemporary identities of the two service entities generated by the secondmodule.

The beneficial effect brought by the technical solutions in accordancewith the embodiments of the present invention is that, real genericauthentication architecture is provided, wherein the authenticationmechanism provided by the GAA can perform negotiating and choosing formultiple authentication mechanisms and authentication modules, whichenhances the flexibility and generality of the authentication mechanism.In the framework according to the embodiments of the present invention,a service provider can be an application server in the mobile network,an application server in the open network, or a mobile terminal withpowerful functions, which enables the service subscriber to use moreabundant service resources. The authentication solution supports thesituation that the mobile terminal is upgraded to be a service provider,which satisfies the demand that the mobile terminal with powerfulfunctions desires to provide services.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating the architecture of a GenericAuthentication Architecture (GAA).

FIG. 2 is a diagram illustrating the architecture of a GAA in 3GPP2 inthe prior art.

FIG. 3 is a schematic diagram illustrating the architecture ofend-to-end communication authentication based on mobile networksaccording to the embodiments of the present invention.

FIG. 4 is a flow chart illustrating the process of negotiating theauthentication mechanism and performing mutual authentication between aservice entity and an entity authentication centre in an embodimentaccording to the present invention.

FIG. 5 is a flow chart illustrating the process of authenticationinquiring between a service entity and an entity authentication centrein an embodiment according to the present invention.

FIG. 6 is a schematic diagram illustrating an end-to-end authenticationmodel combined with a Kerberos model.

FIG. 7 is a block diagram illustrating the process of authenticationinquiring combined with a Kerberos model.

FIG. 8 is a schematic diagram illustrating an end-to-end authenticationmodel combined with a Mediation model.

FIG. 9 is a block diagram illustrating the process of authenticationinquiring combined with a Mediation model.

FIG. 10 is a flow chart illustrating a method for authenticating serviceentities in an embodiment according to the present invention.

FIG. 11 is a flow chart illustrating a method for authenticating serviceentities in a 3GPP radio network according in an embodiment according tothe present invention.

FIG. 12 is a flow chart illustrating a method for authenticating serviceentities in a 3GPP2 radio network in an embodiment according to thepresent invention.

FIG. 13 is a flow chart illustrating a method for authenticatingmutually between a SP and an entity authentication centre, in case thatthe SP is a bank, in an embodiment according to the present invention.

FIG. 14 is a schematic diagram illustrating the structure of anembodiment of an authentication apparatus according to the embodiment ofthe present invention.

FIG. 15 is a flow chart illustrating the process of authenticationbetween a service subscriber and an entity authentication centre in anembodiment according to the present invention.

FIG. 16 is a flow chart illustrating the process of mutualauthentication between a service subscriber and a service provider in anembodiment according to the present invention.

FIG. 17 is a flow chart illustrating the process of a service subscriberand a service provider reusing the authentication result to generate asession key in an embodiment according to the present invention.

FIG. 18 is a schematic diagram illustrating the structure of anembodiment of an end-to-end communication authentication apparatusaccording to the present invention.

DETAILED DESCRIPTIONS OF THE EMBODIMENTS OF THE INVENTION

The present invention is hereinafter further described in detail withreference to the accompanying drawings as well as embodiments so as tomake the objective, technical solution and merits thereof more apparent.

FIG. 3 illustrates the architecture of an end-to-end communicationauthentication based on mobile networks according to an embodiment ofthe present invention. The architecture can be called genericauthentication architecture in deed in that it is applicable fordifferent mobile network standards and serves to establish a mutualtrust relationship between different types of service entities. Besidestwo service entities, Service Subscriber (SS) 301 and Service Provider(SP) 302, the network elements involved in the generic authenticationarchitecture further includes Entity Authentication Centre (EAC) 303 andEntity Subscription Database (ESD) 304 in the operator's network. In thearchitecture, the SS and the SP can communicate with each other, and theSS and the SP can respectively communicate with the EAC to perform theirown authentication, and the EAC can connect with an ESD from which theinformation needed by authentication can be acquired. In the embodimentsof the present invention, a service entity can be a service subscriber(SS) or a service provider (SP). The SS can be equivalent to thesubscriber in the 3GPP GAA or the MN in the 3GPP2 GAA, the SP can behaveas the NAF in the 3GPP GAA or in the 3GPP2 GAA, and the EAC can beequivalent to the BSF in the 3GPP GAA or in the 3GPP2 GAA.

When providing a service to a mobile subscriber, a majority ofapplication servers first establish with the mobile subscriber a mutualtrust relationship (for example, the trust relationship between themobile subscriber and the authentication proxy, that between the mobilesubscriber and the PKI certificate organization, that between the mobilesubscriber and the content providing server, and the like). Generally,such trust relationship is established during the bidirectionalauthenticating procedure between the mobile subscriber and theapplication server. Along with the development of the mobile network,the types of the services are increasingly diversified. Meanwhile, theSP is not limited to the pure operator network, but can be a third partySP other than the operator network or even a mobile subscriber. That is,some mobile subscribers not only can use the application servicesprovided by the network but also can provide some services to othersubscribers in the network. There are three types of SPs in theembodiments of the present invention, including an AS of the operatornetwork, a third party AS and a mobile subscriber. And there are twotypes of SSs, including a common mobile subscriber or a third party AS.Thus, the mobile subscriber can be the SS as well as the SP while thethird party AS can be the SP and the SS. Therefore, as compared with thedivision of service entities into a subscriber and a SP, the serviceentities, in the embodiments of the present invention, are divided intothree types: 1. an SS, a simple service subscriber which can only applyfor services (generally is a common mobile subscriber), 2. an SP, asimple service provider (an AS of the operator network or an SP of anexternal network), 3. a service subscriber and provider (also referredas SSP) which is not only a service subscriber but also a serviceprovider (can be a common mobile subscriber or a third party AS).

In the architecture illustrated in FIG. 3, the EAC is used fornegotiating the authentication method and authenticating the serviceentity, and verifying the identity of end-to-end communication entitiesand the validity of the entity's requesting or providing services, andgenerating the derived key etc. The ESD stores the subscriptioninformation of the entity including the type of the service subscribedand/or provided by the entity, the authentication mechanism supported bythe entity and authentication information, and so on. The subscriptioninformation of the entity is stored together with the private ID of theentity. Before the SP provides services to other entities or the SSrequests services of other entities, a subscription relationship betweenthe SP and the network or that between the SS and the network shouldexist and should be stored in the ESD.

The authentication procedure provided by the embodiments of the presentinvention includes the following stages.

The first stage (referred as an entity authentication process): theservice entity first has to go to the EAC to negotiate theauthentication mechanism and authenticate the identity of the serviceentity before each SS in the network communicates with the SP.

The process for negotiating the authentication mechanism is initiated bythe service entity and the identity of the service entity and thesecurity degree requirement of the service are carried in the requestmessage for initiating the negotiation. The EAC selects anauthentication mechanism according to the security degree, the networksupport conditions (e.g., the authentication modes the networksupported) and entity subscription information, and returns thecorresponding information to the service entity behaving as theauthentication requester. Different security degrees of the service leadto different authentication modes selected. The authentication requesterissues a conformation message to denote the end of negotiationprocedure.

The service entity and the EAC will perform a mutual authenticationbetween them according to the negotiated mechanism. The authenticationis bidirectional. After the authentication, the authentication requester(namely the service entity requesting the authentication) and the EACgenerate a shared key material, and the EAC allocates a temporary ID anda corresponding life time to the authentication requestor according toits subscription information. If the authentication requester is an SS,the EAC will allocate an Interim Service Request Identifier (ISR-ID) toit, and if the authentication requestor is an SP, the EAC will allocateto it an Interim Authentication Check Identifier (IAC-ID). The EACtransfers the temporary ID of the service entity and the lifetime to theservice entity requesting authentication. After this, the communicationbetween the service entity requesting authentication and the EAC can beprotected by using the shared key material generated in theauthentication procedure between the service entity and the EAC.

The second stage (referred as an authentication inquiring process):

After performing the authentication with the EAC, the SS can request theSP for a service.

Upon the reception of the service request, if the SP or SSP hasperformed the authentication with the EAC and has acquired a validIAC-ID, the SP or SSP can inquire of the EAC about the authenticationcondition of the SS. Otherwise, the SP or SSP has to communicate withthe EAC first to perform the authentication and the key negotiation, andinquire of the EAC about the authentication condition of the SS bysending an inquiry request which carries the ISR-ID of the SS and theIAC-ID of the SP or SSP. Upon receiving the inquiry request, the EACfirst inquires whether the SS and the SP have the authority according tothe ID of the SS and that of the SP, then calculates a derived key forprotecting the service communication between the SS and the SP by usingtheir temporary IDs and the Ks negotiated with the EAC by the SS/SP, andtransfers the derived key to the SP. Meanwhile, the SS calculates thederived key according to the same parameters and algorithm. The trustrelationship established between the service entity and the EAC has alifetime. If the lifetime is about to expire or has expired, the serviceentity needs a re-authentication procedure with the EAC to establish anew trust relationship.

The third stage (referred as a mutual authentication process betweenservice entities): after acquiring the shared derived key, the SS andthe SP may use the derived key to perform the mutual authenticationbetween the two parties before each service communication, furthergenerate a session key, Kr-SS-SP, for protecting the security of thecommunication, and then use the session key to protect the servicecommunication.

Each stage of the authentication procedure provided by the embodimentsof the present invention will be described in detail with reference tothe attached drawings.

FIG. 4 is a flow chart illustrating the process of negotiating theauthentication mechanism and performing the mutual authenticationbetween the service entity and the EAC in an embodiment according to thepresent invention. In this embodiment, the process of negotiating theauthentication mechanism and performing the mutual authenticationbetween the service entity and the EAC is initiated by the serviceentity as shown in FIG. 4, and includes the following steps.

Block 401: the service entity automatically chooses a security degreerequirement (for example, a high security degree) of the authenticationmechanism corresponding to the requested service or the provided service(for instance, a video conference service).

Block 402: the service entity transfers to the EAC an authenticationrequest carrying the related information such as the ID of the serviceentity, the security degree of the authentication mechanism chosen bythe service entity, and etc.

Block 403: upon receiving the authentication request, the EAC searchesthe security degree list stored in local to find at least oneauthentication mechanism currently supported by the network andsatisfying the security degree requirement, including an authenticationprotocol and an enciphering algorithm. For instance, Http AKA is amutual authentication protocol between the network and the terminal inthe radio network. By performing this protocol, the two communicationparties can authenticate the identity of each other and generate thesame key respectively. Block 404: according to the identity of theservice entity, the EAC inquiries the subscription information stored inthe ESD and gets the authentication information of the service entity,for example, the authentication mechanism supported by the serviceentity, which includes the authentication protocol, the encipheringalgorithm, and other related parameters.

Block 405: the ESD returns to the EAC the authentication capabilityinformation (i.e., the supported authentication protocol, encipheringalgorithm and etc) and other related parameters of the service entities.

Block 406: the EAC matches the authentication protocols and encipheringalgorithms supported by the service entity and the network, according tothe local policy, and determines the authentication protocol andenciphering algorithm (that is, the authentication mechanism) supportedby both sides which is also in accord with the security degreerequirement. If there is no authentication protocol and encipheringalgorithm supported by both sides which is also in accord with thesecurity degree requirement, the EAC returns an error indication to theservice entity and terminates the current procedure.

Block 407: the EAC returns the chosen authentication mechanism includingthe authentication protocol and enciphering algorithm to the serviceentity.

Block 408: upon receiving the information returned by the EAC, theservice entity decides the authentication mechanism and returns aconfirmation response to the EAC.

Block 409: the service entity and the EAC use the chosen authenticationprotocol and enciphering algorithm to perform mutual authentication.After the successful authentication, both parties acquire the shared keymaterial (also referred as shared secret information).

If the service entity is a mobile terminal, the shared key material canbe a shared key (Ks). If the service entity is an application server(AS) in a mobile core network domain, the shared key material negotiatedin the mutual authentication procedure between the service entity andthe EAC may be a Security Association (SA), that is, a key and keyalgorithm information of security communication negotiated according tothe Internet Protocol Security (IPSec).

Block 401: the EAC returns an authentication success response to theservice entity and allocates a temporary ID for the service entity andthe corresponding lifetime, including the following situations: 1) ifthe service entity issuing the authentication request to the EAC is aservice subscriber (SS/SSP), the EAC will allocate an ISR-ID to theSS/SSP which is to be used if the SS/SSP requests other entities forservices; 2) if the service entity issuing the authentication request tothe EAC is a service provider (SP/SSP), the EAC will allocate an IAC-IDto the SP/SSP which is to be used if it needs to inquire the EAC aboutthe authentication condition of the SS.

Block 411: the EAC and the service entity respectively stores the sharedkey material which is associated with the corresponding security degree,including: associating and storing the ISR-ID/IAC-ID, the key material,the authentication mechanism and the security degree.

FIG. 5 is a flow chart illustrating an authentication inquiringprocedure between a service entity and an EAC in an embodiment accordingto the present invention. In this embodiment, after performing themutual authentication, the service entity and the EAC will perform theauthentication inquiring procedure, the detailed description of which isas shown in FIG. 5.

Block 501: a SS (or SSP) issues a service request to a SP (or anotherSSP) able to provide services, including the ISR-ID acquired by the SSin the authentication with the EAC and a public identity (UID) of the SPwhich is an ID for contacting with other service entities.

Different services provided by the same service entity correspond todifferent UIDs, so different services can be differentiated by their ownUIDs.

Block 502: upon receiving the service request, the SP searches whetherthere is the ISR-ID of the SS stored locally to identify the SS. Ifthere is the ISR-ID, the valid derived key associated therewith, thereal identity information of the service entity and etc., stored, the SSand SP will use the derived key to protect the service between them. Iffinding that the derived key or the ISR-ID information is in ahypo-operation state or has been withdraw or destroyed, the SP notifiesthe SS that a re-authentication request should be initiated and thecurrent procedure is terminated, wherein the detailed procedure ofinitiating the re-authentication is referred to the following text. Ifthe ISR-ID is not stored, the SP sends an authentication inquiringrequest to the EAC and carries the ISR-ID of the SS and the IAC-ID andUID of the SP in the authentication inquiring request, and performsBlock 503.

Block 503: upon receiving the authentication inquiring request, the EACfirst inquires and decides whether the IAC-ID carried in theauthentication inquiring request is valid and whether the SP is entitledto provide the service, and inquires and decides whether the ISR-IDcarried in the authentication inquiring request is valid and whether theSS is entitled to request the service. If it is decided that the IAC-IDis valid and the SP is entitled to provide the service besides theISR-ID is valid and the SS is entitled to request the service (namelypassing authentication), the EAC generates a derived key for the SS andSP.

Block 504: the EAC returns to the SP an authentication inquiringresponse which carries the derived key generated in Block 503 and thelifetime of the key. If the authentication inquiring in Block 503 issuccessful (that is, the result of the inquiry and decision is yes), thenewly derived key which is acquired by enciphering the shared keymaterial of the SP and EAC, is carried in the returned authenticationinquiring response. Otherwise, the EAC returns an error message,notifies the corresponding service entity of re-authenticating at theEAC, the detailed processing of which is referred to the following text,and terminates the current procedure.

Block 505: the SP acquires the newly generated derived key from theauthentication inquiring response by decrypting, and associates thederived key, the lifetime, the ISR-ID of the SS and the UID of the SPand stores them in local.

Block 506: the SP returns a service request response to the SS.

Block 507: the SS calculates the same derived key by using the sameparameters and key algorithm which may adopt the Data EncryptionStandard (DES), the ternary DES (3-DES), the Advanced EncipheringStandard (AES) 256, AES 1024 and etc., wherein both 256 and 1024represent the key length.

Block 508: the SS and the SP use the derived key to protect the servicebetween them.

Since the trust relationship established between the service entity andthe EAC by the authentication has a lifetime (such as the lifetime ofthe shared key material, the derived key, and the temporary ID), if thelifetime is about to expire or has expired, the service entity needs toconnect with the EAC for the re-authentication between them to establisha new trust relationship.

Additionally, according to the different conditions of the shared keymaterial or the temporary ID, the service entity may have the followingstates: 1. a hypo-operation state: the shared key material, the lifetimeof the derived key or the temporary ID is about to expire, therefore theshared key material can not be used in enciphering calculation but canbe used in decrypting and authenticating the entity ID; 2. a withdrawstate: the shared key material, the lifetime of the derived key or thetemporary ID has expired, and the corresponding relationship between theshared key material and the real ID of the entity or the correspondingrelationship between the temporary ID and the real ID of the entity hasbeen removed; 3. a destroyed state: the related records of the sharedkey material, the derived key or the temporary ID has been deleted.Thus, in case that at least one of the following situations occurs, itis needed to initiate the re-authentication procedure.

1. if finding, according to the local policy, that the shared keymaterial of the service entity and the EAC or the temporary ID of theservice entity is in the hypo-operation state, the EAC notifies theservice entity that the re-authentication request should be initiated.

2. if finding, according to the local policy, that the shared keymaterial or the temporary ID is in the withdraw or destroyed state, theEAC notifies the service entity that the re-authentication requestshould be initiated.

3. if the EAC can not find the related identity information and keyinformation according to the temporary ID (that is, in the destroyedstate), the EAC notifies the service entity that the re-authenticationrequest should be initiated.

4. if finding, according to the local policy, that the derived key is inthe hypo-operation state, the SP notifies the SS that there-authentication request should be initiated.

5. if finding, according to the local policy, that the derived key is inthe withdraw or destroyed state, the SP notifies the SS that there-authentication request should be initiated.

6. if the SP can not find, according to the temporary ID, thecorresponding identity information and key information (that is, in thedestroyed state), the SP notifies the SS that the re-authenticationrequest should be initiated.

When the EAC notifies the service entity that the re-authenticationrequest should be initiated, the reason for the re-authentication isidentified in the notification. If the reason for re-authentication isthat the shared key material or the temporary ID is in thehypo-operation state, the service entity will use the temporary ID toidentify itself in the initiated re-authentication request. Uponreceiving the re-authentication request, the EAC decides, according tothe temporary ID, that it doesn't need to negotiate the authenticationmechanism, and thus adopts the originally used authentication mechanismto perform the mutual authentication. If the reason for there-authentication is that the shared key material or the temporary ID isin the withdraw or destroyed state, or the key material can not be foundaccording to the temporary ID when needed, the service entity will usethe private ID to identify itself in the initiated re-authenticationrequest. Upon receiving the re-authentication request, the EAC decides,according to the private ID, that it is needed to negotiate theauthentication mechanism, wherein the procedure of re-negotiatingauthentication mechanism is the same as the initial authenticationprocedure as shown in FIG. 4.

Similarly, when the SP notifies the SS that the re-authenticationrequest should be initiated, the reason for the re-authentication shouldalso be identified in the notification. If the reason forre-authentication is that the temporary ID is in the hypo-operationstate, the SS will use the temporary ID to identify itself in theinitiated re-authentication request. Upon receiving there-authentication request, the EAC decides, according to the temporaryID, that it doesn't need to negotiate the authentication mechanism, andthus uses the originally used authentication mechanism to perform themutual authentication. If the reason for re-authentication is that thetemporary ID is in the withdraw or destroyed state, the SS will use theprivate ID to identify itself in the initiated re-authenticationrequest. Upon receiving the re-authentication request, the EAC decides,according to the private ID, that it doesn't need to negotiate theauthentication mechanism, wherein the procedure of re-negotiatingauthentication mechanism is the same as the initial authenticationprocedure as shown in FIG. 4.

If using the temporary ID (i.e., ISR-ID/IAC-ID) or the shared keymaterial (i.e., Ks/Kp) associated therewith, the service entities (SS orSP) or the EAC should verify whether the temporary ID or the shared keymaterial is in the hypo-operation, withdraw or destroyed state. If thetemporary ID or the shared key material is in the hypo-operation,withdraw or destroyed states, the service entity or the EAC shouldinitiate a re-authentication procedure between the corresponding serviceentity and EAC. In the authentication procedure, if receiving a messageindicating the failure reasons, the service entity or the EAC may alsoinitiate the re-authentication procedure. Moreover, if the SP finds thatthe shared derived key with the SS is in the hypo-operation, withdraw ordestroyed states, it sends a re-authentication request to the SS andindicates the re-authentication reason in the request. And if only theshared derived key is in the hypo-operation, withdraw or destroyedstates while the temporary IDs of the SS and SP is in the normal state,the SS and SP need not perform the original entity authentication withthe EAC, the SS should originates the authentication inquiring procedureto the EAC, so that the EAC would generate a new shared derived key forthe SP, and the SS would generate the same shared derived key by itself.

Herein lies the example of the lifetime and the hypo-operation state.Taking the lifetime of the shared key material as an example, assumingthat the lifetime of the shared key material is 48 hours and that in theperiod from 44 hours to 48 hours it is in the hypo-operation state, ifthe shared key material has been live for 45 hours, it can be decidedthat the shared key material is in the hypo-operation state of its livecycle.

If the Entity Authentication Centre (EAC) has the functions of aKerberos server, the mechanism of authentication inquiring combined withthe Kerberos model can be used. FIG. 6 is a schematic diagramillustrating an end-to-end authentication model combined with theKerberos model. As shown in FIG. 6, a SS makes a request to the EAC fora service granted ticket (SGT) and provides the ISR-ID of the SS and theUID to the EAC. The EAC checks the validity of the ISR-ID and theIAC-ID, generates the service granted ticket and returns the servicegranted ticket to the SS. When issuing the service request to the SP,the SS carries the service granted ticket in the request. The SPgenerates a derived key according to the service granted ticket and thenreturns the SS a service response.

FIG. 7 is a schematic diagram illustrating the process of authenticationinquiring combined with the Kerberos model illustrated in FIG. 6. Asshown in FIG. 7, the detailed steps are as follows:

Block 701: when desiring to acquire a certain service, the SS firstsearches whether the service granted ticket corresponding to the servicehas been stored locally. If it has been stored, go to Block 705. If ithas not been stored, the SS transfers to the EAC a service grantedticket request carrying the ISR-ID of the SS and the UID of the SPproviding the service.

Block 702: upon receiving the service granted ticket request, the EACchecks the validity of the identity and authority. First, the EACdecides whether the SS is entitled to use the service by inquiringwhether the ISR-ID carried in the request is valid, and then acquiresthe IAC-ID of the SP according to the UID of the SP carried in therequest, and decides whether the SP is entitled to provide the serviceby deciding whether the IAC-ID is valid.

If the above decision shows that the SP is entitled to provide theservice (that is, the SP is legal), the EAC calculates, according to theidentities of the SS and SP, and the shared key material of the SS andthe EAC, a derived key K-SSP/SP for protecting the service communicationbetween the SS and the SP. The EAC further generates a service grantedticket including the derived key and the identities of the SS and theSP, and uses the shared key material of itself and the SP to encipherthe SGT.

If the decision shows that the SP is not entitled to provide the service(namely, the SP is illegal), the EAC will transfer an error message andnotify the corresponding entity of authenticating its identity at theEAC and terminate the current procedure.

Block 703: the EAC transfer the above enciphered SGT to the SS.

Block 704: upon receiving the SGT, the SS locally generates the samederived key with the one the EAC generates by adopting the sameparameters and algorithm used by the EAC.

Block 705: the SS transfers to the SP a service request which caries theSGT.

Block 706: the SP decrypts the SGT to acquire the derived key.

Block 707: the SP returns a service request response identifying successto the SS.

Block 708: the SS and the SP use the derived key to protect the servicebetween them.

Other than the above blocks, the EAC can use the shared key material ofitself and the SS to encipher the derived key and transfer theenciphered derived key to the SS. Thus, the SS can acquire the derivedkey by decrypting instead of re-calculating locally.

Similarly, after acquiring the shared derived key, the SS and the SP mayuse the derived key to perform the mutual authentication between the twoparties before each service communication starts, and further generate asession key, Kr-SS-SP, for protecting the security of the communication,and then use the session key to protect the service communication.

If the EAC has the functions of the Trusted Third Party (TTP) serving asan interceder, the mechanism of authentication inquiring combined with aMediation model can be adopted as well. FIG. 8 is a schematic diagramillustrating an end-to-end authentication model combined with theMediation model. As shown in FIG. 8, the SS issues a service request tothe EAC to request the service provided by the SP. The EAC forwards theservice request to the SP after deciding that the SS is legal. The SPreturns a service request response carrying its own IAC-ID to the EAC.The EAC decides the validity of the SP according to the IAC-ID. If theSP is legal, the EAC calculates the derived key between the SS and theSP and transfers the derived key to the SP and returns a service requestresponse to the SS at the same time. The SS calculates a same derivedkey upon receiving the response.

FIG. 9 is a flow chart illustrating the process of authenticationinquiring combined with the Mediation model shown in FIG. 8. As shown inFIG. 9, the detailed blocks are as follows:

Block 901: if desiring to use a service provided by an SP, an SS firstissues to the EAC a service request which carries the ISR-ID of the SSand the UID of the SP.

Block 902: the EAC decides the validity of the ISR-ID of the SS and thesubscription information of the SS to decide whether the SS is entitledto request the service.

Block 903: if the SS is legal, the EAC forwards the service request tothe SP and performs Block 904. If the SS is illegal, the EAC transfersan error message to the SS to notify the SS of authenticating itsidentity at the EAC and terminates the current procedure.

Block 904: the SP returns a service request response carrying its ownIAC-ID.

Block 905: the EAC verifies the validity of the IAC-ID and thesubscription information of the SP to decide whether the SP is entitledto provide the service. If the SP is legal, the EAC calculates a derivedkey for protecting the service communication between the SS and the SPaccording to the identities of the SS and the SP and the shared keymaterial of the SS and the EAC, and performs Block 906. If the SP isillegal, the EAC transfers an error message to the SP to notify the SPof authenticating its ID at the EAC, and terminates the currentprocedure.

Block 906: the EAC transfers a service request success response to theSS and transfers to the SP the derived key enciphered by the shared keymaterial of the EAC and the SP.

Block 907: upon receiving the service request success responsetransferred by the EAC, the SS adopts the same parameters and algorithmused by the EAC to acquire the derived key.

Block 908: the SS and the SP use the derived key to protect the servicebetween them.

Similarly, after acquiring the share derived key, the SS and the SP mayuse the derived key to perform the mutual authentication between the twoparties before each service communication starts, and further generate asession key, Kr-SS-SP, for protecting the security of the communication,and then use the session key to protect the service communication.

The foregoing statement just illustrates the embodiments of the presentinvention. In other similar situations, such as the SSP serving as aservice entity, the figure of the SSP can be varied. In case that theSSP requests a service, its processing manner is the same as that of theabove SS while in case that the SSP provides a service, its processingmanner is the same as that of the SP. Therefore, the general variationsand replacements occurred within the scope of the embodiments of thepresent invention and made by those skilled in the art should be coveredby the protection scope of the present invention.

embodiments of the authentication procedures of the first stage andsecond stage in the authentication method of the embodiments accordingto the present invention are described hereinafter.

FIG. 10 is a flow chart illustrating a method for authenticating serviceentities in an embodiment according to the present invention. Referringto FIG. 10, the descriptions of the authentication method according tothe present invention are as follows.

Block 1001: a service entity transfers to the EAC an authenticationrequest carrying the identity information of the service entity,security degree information, the information of at least oneauthentication mechanism supported by the service entity (if theinformation of the at least one authentication mechanism supported bythe service entity is stored in the subscription information of thenetwork, the information of the authentication mechanism may not becarried), and etc.

The identity information may include a private ID (PID) or a UID. Withrespect to selecting a security degree, the following situations may beconsidered 1) The service entity may select the security degreecorresponding to the desired service by searching the service securitydegree list stored in local. 2) If the service entity does not store thesecurity degree list locally, the security degree may be selected by thesubscriber manually through a human-computer interface. 3) The serviceentity may only provide the UID of the SP providing the correspondingservice to the EAC without selecting the security degree, wherein theUID can identify the type of the service provided by the SP. Then, theEAC can search the security degree list according to the type of theservice thereby selecting the corresponding security degree.

Block 1002: upon receiving the authentication request, the EAC searchesthe subscription information stored in the ESD according to the ID inthe request, and selects an authentication mechanism according to thelocal policy considering the authentication mechanism, supported by theservice entity and the network, and the security degree. Theauthentication mechanism selected in this embodiment is identified asauthentication mechanism b. The supported authentication mechanism mayinclude AKA, SIM, CAVE, MN-AAA key, TLS-PSK or TLS-Cert, DH and etc.

When the network and the service entity only support one authenticationmechanism, the two parties can adopt the authentication mechanism toperform mutual authentication without negotiation. When selecting thesecurity degree, the EAC may consider the security degree requirement ofthe service or not, that is, the security degree as a condition isoptional for the authentication negotiation procedure.

Block 1003: the EAC transfers to the service entity an authenticationinitialization message carrying the identifier of the authenticationmechanism selected in Block 1002, and the security degree (if thesecurity degree is considered in the negotiation procedure in Block1002, the security degree should not be lower than the security degreeselected by the service entity), and etc.

If the follow-up authentication interaction procedure is initiated bythe EAC, the authentication initialization message should include theinformation carried by the first authentication message in the procedurebade on the authentication mechanism. The contents of the firstauthentication message, in terms of the AKA authentication, areauthentication vectors, while in terms of the TLS authentication manner,the contents are Hello Request.

Block 1004: the service entity obtains the authentication mechanism. Ifthe follow-up authentication is initiated by the service entity, theservice entity calculates the authentication information, while if thefollow-up authentication is initiated by the EAC, the service entitywill calculate the response value after receiving the relatedauthentication information.

Block 1005: the authentication interaction procedure based on theselected authentication mechanism is performed between the serviceentity and the EAC.

Block 1006: after the authentication, both the service entity and theEAC get the shared key material and the EAC allocates to the serviceentity an ISR-ID or IAC-ID which is stored associated with the sharedkey material and can serve as an index for searching the shared keymaterial or a Session ID of a security connection.

FIG. 11 is a flow chart illustrating a method for authenticating serviceentities of a 3GPP radio network in an embodiment according to thepresent invention. Referring to FIG. 11, in this embodiment, the serviceentity is an SS. In case that the SS is a mobile terminal in the 3 GPPnetwork, namely a UE in FIG. 11, and only supports the AKAauthentication, the authentication procedure is as follows.

Block 1101: a UE issues to the EAC a HTTP Digest authentication requestcarrying its own ID.

Block 1102: since the 3GPP network and the UE only support the AKAmechanism, the two parties directly adopt the AKA mechanism toauthenticate without negotiating the authentication mechanism. From theESD, the EAC obtains the authentication vector of the UE subscriber(RAND, AUTN, RES, CK, IK).

Block 1103: the EAC transfers to the UE a HTTP 401 message (includingDigest AKA challenge), carrying the RAND and the AUTN in theauthentication vector.

Block 1104: the UE calculates and verifies the validity of the AUTN toconfirm whether the message including the Digest AKA challenge comesfrom an authorized network, and calculates the CK, IK, and RES.

Block 1105: the UE transfers to the EAC an HTTP request messageincluding a Digest AKA response and an abstract value calculated by theRES calculated.

Block 1106: the EAC verifies the accuracy of the calculated abstractvalue to authenticate the validity of the UE.

Block 1107: the EAC generates a key material, Ks=CK∥K, and ISR-ID, thegenerating method and format of which are the same as those of the B-TIDin the 3GPP generic authentication architecture.

Block 1108: the EAC transfers to the UE a 200 OK message to identify thesuccessful end of the authentication, wherein the message which isenciphered by the Ks includes the life time of the key material and theISR-ID.

Block 1109: the UE also generates the same key material, Ks=CK∥K,acquires the ISR-ID and the lifetime of the key material by decrypting,stores the ISR-ID and the lifetime of the key material in local, andassociates them with the authentication mechanism.

FIG. 12 is a flow chart illustrating a method for authenticating serviceentities in a 3GPP2 radio network in an embodiment according to thepresent invention. In this embodiment, the service entity is an SS. Incase that the SS is a UE and supports such authentication methods as theAKA authentication, certificate authentication and etc., while the 3GPP2network supports the AKA authentication, CAVE-based authenticationmechanism, and MN-AAA-based authentication mechanism, the authenticationprocedure is as follows referring to FIG. 12.

Block 1201: the UE issues to the EAC an HTTP authentication requestcarrying the identity of the UE and the authentication modes the UEsupported, such as the AKA authentication and the certificateauthentication.

Block 1202: the EAC searches in the ESD the UE's subscriptioninformation according to the UE's identity, and decides that the twoparties use the AKA mechanism to perform authentication by adopting thelocal policy according to the self-supported authentication mechanismtypes, such as the AKA authentication, CAVE-based authenticationmechanism, and MN-AAA-based authentication mechanism. The EAC acquiresfrom the ESD the UE subscriber's authentication vector, (RAND, AUTN,RES, CK, IK).

Block 1203: the EAC transfers to the UE an HTTP 401 message (includingDigest AKA challenge) carrying RAND and AUTN, and puts theauthentication mechanism identifier in the payload information of thismessage.

Block 1204: the UE calculates and verifies the accuracy of the AUTN toconfirm whether the message including the challenge comes from anauthorized network, and calculates the CK, IK, and RES.

Block 1205: the UE sends to the EAC an HTTP request message includingDigest AKA response and an abstract value calculated by the RES.

Block 1206: the EAC verifies the accuracy of the abstract value toauthenticate the validity of the UE.

Block 1207: the EAC generates a key material, Ks=CK∥K, and the ISR-ID,the generating method and format of which are the same as those of theB-TID in the 3GPP2 generic authentication architecture.

Block 1208: the EAC sends to the UE a 200 OK message to identify thesuccessful end of the authentication, wherein the message is encipheredby the Ks and includes the ISR-ID and the lifetime of the key material.

Block 1209: the UE also generates the same Ks=CK∥K, and then acquiresthe ISR-ID and the lifetime of the key material by decrypting,associated the ISR-ID and the lifetime of the key material with theauthentication mechanism, and stores them in local.

After receiving the authentication request, if the UE supports theCAVE-based authentication mechanism as well, the EAC searches thesubscription information according to its own identity, and eventuallydecides the CAVE-based authentication mechanism should be used byadopting the local policy, considering the types of authentication modesit supports, and the flow-up authentication procedure is the same as theCAVE-based authentication procedure in the 3GPP2 generic authenticationarchitecture. If it is decided to use the AAA authentication mechanism,the generic authentication architecture in the embodiments of thepresent invention can also be used according to the same principle.

FIG. 13 is a flow chart illustrating a method for authenticatingmutually between a SP and an entity authentication centre, in case thatthe SP is a bank, in an embodiment according to the present invention.In this embodiment, the service entity is a bank SP. When the bank SPdesires to provide a mobile phone bank service for a UE, it first needsto perform mutual authentication with the EAC to generate a shared keymaterial and establish a security connection, and the authenticationprocedure is as follows, referring to FIG. 13.

Block 1301: a SP transfers to the EAC an authentication request carryingits own UID.

Block 1302: the EAC searches the subscription information of the SPaccording to the UID, and after deciding that the SP is entitled toprovide the service, acquires the information of authenticationcapability of the SP, that is, the authentication modes supported by theSP, such as the certificate, the certificate TLS authentication, thepre-shared key-based TLS authentication, and etc.

Then, the EAC searches the service security degree list, decides thatthe mobile phone bank service belongs to the high security degreeservice, and finds that the authentication modes supported by thenetwork with the high security degree include the HTTP Digest AKA, thecertificate TLS authentication, and etc by searching the authenticationsecurity degree list. And the EAC eventually matches the authenticationmechanism supported by the SP and determine the authentication mechanismused in the mutual authentication. In this embodiment, it is decided touse the certificate TLS.

Block 1303: the EAC initiates to the SP a Hello Request message carryingan authentication mechanism identifier (in this embodiment, is theidentifier of the certificate TLS authentication) and a security degreeidentifier.

Block 1304: the SP learns that the authentication mechanism is thecertificate TLS, searches whether there is locally a Session ID: IAC-ID.If a TLS security channel has been established through the certificateTLS authentication of the EAC and the channel is still valid, theSession ID can be an index of the TLS security channel.

Block 1305: the SP transfers a Client Hello message to the EAC. If theSP has not stored a valid Session ID, the Session ID filed of themessage is null, and if the SP has stored a valid Session ID: IAC-ID,the Session ID field of the message is the IAC-ID.

Block 1306: upon receiving the Client Hello message, the EAC verifieswhether the Session ID field is null. If the Session ID field is notnull and associated security connection information can be matched withthe information carried in the Session ID field, the EAC directlytransfers a Finished message to the SP to verity whether theauthentication result of the security connection and the shared keymaterial are available. After verifying that the parameters in theFinished message are correct, the SP returns another Finished message tothe EAC. If the EAC verifies that the parameters in the Finished messageare correct, the two parties re-use the security connection.

If the Session ID file is null or the above Finished message has anerror, the EAC returns in turn a Server certificate message, aServerKeyExchange message (optional), and a CertificateRequest message,according to the parameters in the local policy configuration message.Eventually, the EAC returns a ServerHelloDone message to show that theServerHello and related messages have been transferred.

Block 1307: upon receiving the SelverHelloDone message, the SP returns a

Certificate message and then transfers a ClientKeyExchange messagethrough which the two parties acquire the shared secrete parameters.Then, the SP transfers a CertifiicateVerify message to the EAC tofacilitate the EAC in verifying the certificate of the SP clearly. Atlast, after transferring a ChangeCipherSpec message, the SP transfers aFinished message to the EAC at once to identify that the key exchangeand authentication procedure are successful.

Block 1308: the EAC verifies whether the information in the Finishedmessage of the SP is correct. If the information is not correct,terminate the current handshake procedure, and if the information iscorrect, return another Finished message to the SP. If the SP verifiesthat the information in the Finished message is correct, it means thatthe authentication and key exchange procedure between the two partiesare successful.

This embodiment provides a uniform procedure for authenticating the NAFin the 3GPP/3GPP2 network, which is also applicable for the genericauthentication architecture according to the present invention.

Based on the above embodiments of the present invention, an apparatus ofentity authentication is also provided. FIG. 14 is a structure chartillustrating an embodiment of an apparatus of authentication in theembodiments of the present invention. Referring to FIG. 14, theapparatus of entity authentication includes a module for transferringauthentication requests, a module of negotiation, and a module ofauthentication interaction.

The module for transferring authentication requests is used fortransferring the authentication request for the service entity to theEAC, wherein the contents of the authentication request include theidentity of the service entity. The module of negotiation is configuredto choose an authentication mechanism according to the local policy forthe EAC after receiving the authentication request. The module ofauthentication interaction is used for performing authenticationinteraction based on the chosen authentication mechanism between theservice entity and the EAC. The principles of these modules forperforming the functions have been described in the above procedures,and they will not be described herein.

On the basis of the above authentication solutions, an enhanced solutionis provided by the embodiments of the present invention, including,first defining the authentication mode which on the whole defines theservice entity authentication, the authentication inquiring procedureand the mutual authentication between the service entities, including anauthentication mechanism between the service entity and the EAC, amechanism of authentication inquiring and a mechanism for generating aderived key, an authentication mechanism between the service entities,and a method for generating a session key etc. The solution isillustrated in brief as follows.

1. Defining an authentication mode

An E2E authentication mode can be defined, which is mainly determined bythe authentication mechanism of the SS and the EAC and sometimes by theauthentication mechanism of the SS and the SP. In the authenticationmode, there are several authentication-related modes defined, includingthe authentication mechanism of the SS and the EAC, the authenticationmechanism of the SP and the EAC, the authentication mechanism betweenthe SS and the SP, the mechanism of authentication inquiring, themechanism for generating the derived key, and the mechanism forgenerating the session key etc. in practical applications, only a partof the above authentication-related modes may be defined in theauthentication mode with regard to some cases. For example, in case thatthe SS and the SP can directly authenticate without negotiating theauthentication mechanism and establish a security connection, theauthentication between the SS and the EAC and that between the SP andthe EAC are not necessary. Therefore, in the authentication-related modefor this case, only the authentication mechanism between the SS and theSP and the method for generating the session key should be defined.

In the authentication mode, the choosing policy of each authenticationmechanism can be further defined, including whether the authenticationmechanism is optional or not and whether the authentication methodshould be negotiated or not.

There are several types of End-to-End (E2E) authentication mode whichcan be adopted by the embodiments of the present invention as follows.

E2E_(—)3GPP_AKA, E2E_(—)3GPP2_AKA, E2E_(—)3GPP2_CAVE, E2E_WLAN,E2E_(—)3GPP2_MNAAA, E2E_(—)3GPP_WLAN, E2E_Kerberos, E2E_Mediation,E2E_TLS (however, the definition of the authentication mode is notlimited to these types, and new types can also be defined as required).The embodiments of these types of authentication modes are as follows.

1. Definition of E2E_(—)3GPP_AKA is as follows:

  E2E_3GPP_AKA ::= struct {   SS<->EAC authentication mechanism  AKA  Bearer protocol  HTTP Digest    SP<->EAC authentication mechanism  theTLS mechanism (or the IPSec channel mechanism and etc)    SS<->SPauthentication mechanism  the basic inquiring    mechanism     Bearerprotocol  TLS (or others)     Mechanism for generating the session key self-defined (or others, optional)  }

2. Definition of E2E_(—)3GPP2_CAVE is as follows:

 E2E_3GPP2_CAVE ::= struct {  SS<->EAC authenticationmechanism Authentication based on CAVE  Bearer protocol HTTP Digest  SP<->EAC authentication mechanism TLS mechanism (or IPSec channelmechanism and etc)  SS<->SP authentication mechanism basic inquiringmechanism  Bearer protocol TLS (or others)  Mechanism for generating thesession key self-defined  (or others, optional)  }

3.

    E2E_WLAN ::= struct {   SS<->EAC authentication mechanism  AKA (orSIM)   Bearer protocol  EAP(Extensible Authentication Protocol)  SP<->EAC authentication mechanism  TLS mechanism (or IPSec channelmechanism and etc)    SS<->SP authentication mechanism  basic inquiringmechanism  Bearer protocol  TLS (or others)     Mechanism for generatingthe session key  self-defined (or others, optional)  }

4. Definition of E2E_Kerberos is as follows:

   SS<->EAC authentication mechanism (negotiable, for example, AKA,CABE-based authentication, certificate-based authentication)    SP<->EACauthentication mechanism  IPSec channel    (or others, optional)  SS<->SP authentication mechanism  Kerberos (compulsory, it can benegotiated which one of Kerberos and modified Kerberos solutions shouldbe used)   Bearer protocol  TCP (or others)   Mechanism for generatingthe session key   TLS-Krb5 (or others, optional)  }

5. Definition of E2E_TLS is as follows:

 E2E_TLS ::= struct { SS<->EAC authentication mechanism  none   SP<->EACauthentication mechanism  none    SS<->SP authentication mechanism  TLS Mechanism for generating the session key  TLS-PSK5 (or others, optional)  }

6. Definition of E2E_(—)3G_GAA is as follows:

The authentication mechanism between the SS and EAC may be any of SIM,AKA, CAVE, MN-AAA Key, TLS-PSK, TLS-Cert etc;

The authentication mechanism between SP and EAC may be TLS, IKE;

The mechanism of authentication inquiring and the mechanism forgenerating a derived key is GBA; and

The authentication mechanism between the SS and SP may be TLS-PSK,TLS-Cert.

7. Definition of E2E_KERBEROS is as follows:

The authentication mechanism between the SS and EAC may be those definedin E2E_(—)3G_GAA, and the EAC generates the SGT and send to the serviceentity after authentication;

The authentication mechanism between SP and EAC may be NULL, TLS, IKE;

The mechanism of authentication inquiring and the mechanism forgenerating a derived key is Kerberos; and

The authentication mechanism between the SS and SP may be NULL,TLS-KBR5.

8. Definition of E2E_Mediation is as follows:

The authentication mechanism between the SS and EAC may be IKE, besidesthose defined in E2E_(—)3G_GAA;

The authentication mechanism between SP and EAC may be those defined inE2E_(—)3G_GAA;

The mechanism of authentication inquiring and the mechanism forgenerating a derived key is Mediation; and

The authentication mechanism between the SS and SP is TLS-PSK.

9. Definition of E2E_TLS is as follows:

The authentication mechanism between the SS and EAC is NULL;

The authentication mechanism between SP and EAC is NULL;

The mechanism of authentication inquiring and the mechanism forgenerating a derived key is NULL; and

The authentication mechanism between the SS and SP may be TLS-Cert,TLS-PSK.

In the above modes, new authentication modes can be defined according toservice requirements. The embodiments of the present invention do notlimit the specific authentication-related modes defined in theauthentication mode, such as the authentication mechanism, selectionpolicy, and mechanism for generating the key etc.

FIG. 15 is a flow chart illustrating the of authentication procedurebetween a service subscriber and an EAC in an embodiment of the presentinvention. Referring to FIG. 15, in this embodiment, a UE of a mobilesubscriber in the 3GPP network uses a service provided by an applicationserver in the Internet (the server supports the Kerberos authenticationprotocol). The detailed procedure is as follows.

Block 1501: the SS (i.e., the UE) transfers to the EAC a service requestcarrying the UE's ID, an authentication capability identifier, a servicetype, and the service request may not carry the service type but the UIDof the SP to enable the EAC to search the corresponding service typefrom the Entity Subscription Database (ESC) through the UID.

Block 1502: the EAC selects an authentication mode and the correspondingauthentication mechanism by adopting the local policy according to theID in the service request, the information of the authenticationcapabilities of the SS and SP. In this embodiment, the authenticationmode selected is assumed as the E2E_Kerberos mode.

The EAC is capable of deciding each authentication mechanism accordingto the local policy and the selecting policy in the authentication mode.The local policy can be that the SS and the SP select the mutualauthentication mechanism and the mechanism for generating the sessionkey according to the authentication capabilities of the two parties andthe service type, and whether to perform the mutual authenticationbetween the SP and the EAC can be decided by the mutual authenticationmechanism of the SS and the SP. If it is needed to perform the mutualauthentication, an authentication mechanism would be selected accordingto the authentication capabilities of the SP and the EAC and the servicetype etc.

Block 1503: according to the definition of the E2E_Kerberos mode, theauthentication mechanism of the SS and the EAC is negotiable, thereforethe authentication mechanism can be selected according to the localpolicy (that is, the authentication capabilities of the two parties, thetype of the service to be used by the two parties, and etc.). In thisembodiment, the authentication mechanism of the SS and the EAC isassumed as the AKA authentication mechanism. The authenticationmechanism of the SS and the EAC may be the IPSec channel or others andis optional. In this embodiment, it is assumed that the authenticationmechanism of the SS and the EAC is configured as null, that is, theauthentication between the SP and the EAC will not be performed. Theauthentication mechanism of the SS and the SP is set as Kerberos, so theauthentication mechanism of the SS and the SP can be negotiated bydeciding whether to use the Kerberos or the modified Kerberos solution,and the bearer protocol can be TCP or other by negotiation. In thisembodiment, according to the authentication capabilities of the twoparties, the service type and etc., via negotiation, the Kerberos isselected as the authentication mechanism of the SS and the SP and theTLS-Krb5 is selected as the bearer protocol. The mechanism forgenerating the session key is set as TLS-Krb5 or others and optional,and in this embodiment, the TLS-Krb5 is selected as the mechanism forgenerating the session key.

According to the above-selected various authentication modes, theauthentication between the SS and the EAC can be started. If the SS andthe EAC have performed AKA mutual authentication and the generatedshared key and ISR-ID are sill in the lifetime, the AKA mutualauthentication needn't to be performed, and it is to perform Block 209directly to generate an SGT.

Block 1504: the EAC acquires the subscriber's authentication vector(RAND, AUTN, RES, CK, IK) from the ESD.

Block 1505: the EAC transfers to the UE an HTTP 401 message (including agest AKA challenge) carrying the RAND and AUTN, and carries theauthentication mechanism identifier a in the payload information of themessage.

Block 1506: the UE calculates and verifies the validity of the receivedAUTN to confirm whether the changllenge message comes from an authorizednetwork, and calculates the CK, IK, and RES.

Block 1507: the UE transfers to the EAC an HTTP request messageincluding a Digest AKA response and an abstract value calculated byusing the RES.

Block 1508: the EAC verifies the accuracy of the calculated abstractvalue to authenticate the validity of the UE.

Block 1509: the EAC generates a shared key, Ks=CK∥K, and the ISR-ID, andthen uses the shared key, Ks, the ID of the SS and the UID of the SP togenerate a derived key, Ksp, and carries the generated derived key inthe SGT, the contents of which include the Ksp, the ISR-ID of the SS,the UID of the SP, the lifetime, parameters of avoiding replay attack,and etc, wherein the SGT is enciphered by the shared key of the EAC andSP.

Block 1510: the EAC transfers to the UE a 200 OK message to identify thesuccessful end of the authentication, including the lifetime of theshared key, the ISR-ID, and the SGT enciphered by using the Ks.

Block 1511: the UE also generates the shared key, Ks=CK∥K, and thederived key, Ksp, and then acquires the ISR-ID in the 200 OK message bydecrypting, associates such information acquired by decrypting with theauthentication mode information, and stores the associated informationin local.

FIG. 16 is a flow chart illustrating the process of mutualauthentication between a SS and a SP of in an embodiment according tothe present invention. Referring to FIG. 16, the detailed procedure forof the mutual authentication between the SS and the SP is as follows.

Block 1601: the SS transfers to the SP a ClientHello message carryingthe UID of the SP, the TLS-KRB5 encipher suite supported by the SS, andthe related information of the authentication mode of E2E_Kerberos.

The related information of the authentication mode of E2E_Kerberosrefers to the modes defined, including the authentication mechanismbetween the SS and the SP and the mechanism for generating the sessionkey.

Block 1602: upon receiving the Client Hello message, the SP finds thatthe Session ID field is null, then selects the TLS-KRB5 encipher suitesupported by the two parties, and transfers to the SS a ServerRequestmessage, a ServerHello and a ServerHelloDone message.

Block 1603: upon receiving the ServiceHelloDone message, the SStransfers to the SP a ClientKeyExchange message by which the two partiesacquire the pre-shared secrete parameters (PreMasterSecret). The SS usesthe PreMasterSecret and a random number to generate a session key(MasterSecret). Then the SS transfers a ChangeCipherSpec message to theSP and transfers a Finished message subsequently to the SP for theformal key exchange and validation.

Block 1604: the SP decrypts an SGT, checks the validation of the SGT,acquires the shared derived key, Ksp, uses the shared derived key, Ksp,to decrypt the PreMasterSecret, and generates the session key of the SSand the SP, MasterSecret, according to the PreMasterSecret and a randomnumber. And then, the SP verifies whether the information in theFinished message from the SS is correct. If the information is notcorrect, it terminates the current procedure; otherwise, it performsBlock 1605.

Block 1605: the SP transfers a ChangeCipherSpec message to the SS andtransfers a Finished message to the SS later.

Block 1606: the SS verifies whether the information in the Finishedmessage from the SP is correct. If the SS decides that information inthe Finished message from the SP is correct, it means that theauthentication and key exchange procedure between the two parties hassuccessfully ended.

Block 1607: the SS and the SP start to transfer service communicationdata.

When the session established in the above procedure has not beenoverdue, if the SS transfers a service request to the SP again, thePreMasterSecret generated in the last session can be re-used to generatea new session key (MasterSecret) for this service communication.

FIG. 17 is a flow chart illustrating the process of an SS and SP reusingthe authentication result to generate a session key in an embodimentaccording to the present invention. Referring to FIG. 17, the detailedprocedure is as follows.

Block 1701: the SS transfers to the SP a Client Hello message carryingthe Session ID of the last session occurring last time.

Block 1702: upon receiving the Client Hello message, the SP finds thatthe Session ID in the message is not set as null and is capable ofmatching the security connection information associated with the sessionID, therefore the Session ID is re-used to identify this session.Moreover, the SP transfers to the SS a ServerHello message carrying theSession ID and then transfers a ServerHelloDone message to the SS.

Block 1703: the SS uses the PreMasterSecret shared with the SP togenerate a session key (MasterSecret).

Block 1704: the SS transfers a ChangeCipherSpec message to the SP andtransfers a Finished message to the SP later

Block 1705: after deciding that the received Finished message iscorrect, the SP uses the same PreMasterSecret to generate the sessionkey (MasterSecret).

Block 1706: the SP transfers a ChangeCipherSpec message to the SS andtransfers a Finished message to the SS subsequently.

Block 1707: if deciding that the Finished message received by the SS iscorrect, the mutual authentication between the two parties is terminatedand the service communication data is started to be transferred.

According to the enhanced entity authentication solution based on theauthentication mode, another apparatus of entity authentication isprovided by an embodiment according to the present invention. Theapparatus is similar to the apparatus shown in FIG. 14. FIG. 18 is aschematic diagram illustrating an embodiment of end-to-end communicationauthentication apparatus according to the present invention. Referringto FIG. 18, the apparatus of entity authentication includes a module fortransferring (similar as the module for transferring the authenticationrequest as shown in FIG. 14), configured to transfer an authenticationrequest to the EAC, a module for selecting (similar as the module ofnegotiation shown in FIG. 14), configured to select an authenticationmode according to the authentication request transferred by the modulefor transferring and informing the service entity, and a module ofauthentication, configured to perform authentication between the serviceentity and the EAC or that between the service entities according to theauthentication mechanism selected by the module for selecting. Theprinciples for implementing the specific functions of these modules havebeen described in the above-mentioned procedures, so no moredescriptions will be given for it herein.

Of course, another apparatus of entity authentication can be provided bythe embodiment according to the present invention, which is capable ofrealizing the functions of the above two apparatus. This apparatus mayinclude, a first module, used for performing the functions of theabove-mentioned module for transferring and that for transferring theauthentication request, a second module, used for performing thefunctions of the module for selecting and the module of negotiation, anda third module, used for performing the functions of the module ofauthentication and module of authentication interaction. No moredescription about the apparatus will be given hereinafter.

The foregoing description is only the embodiments of the presentinvention and is not for use in limiting the protection scope thereof.All the modifications, equivalent replacements or improvements in thescope of the spirit and principles of the present invention shall beincluded in the protection scope of the appended claims.

1. A method for authenticating in end-to-end communications based on amobile network, applied to a system including a first service entityrequesting a service, a second service entity providing the service andan Entity Authentication Centre, EAC, the method comprising: negotiatingan authentication mode between the first service entity and the EAC,wherein the negotiated authentication mode comprises: an authenticationmechanism between the first service entity and the EAC, anauthentication mechanism between the second service entity and the EAC,a mechanism of authentication inquiring, a mechanism for generating aderived key, and an authentication mechanism between the first serviceentity and the second service entity; performing a mutual authenticationbetween the EAC and the first service entity according to theauthentication mechanism between the first service entity and the EACcomprised in the negotiated authentication mode, and performing a mutualauthentication between the EAC and the second service entity accordingto the authentication mechanism between the second service entity andthe EAC comprised in the negotiated authentication mode; if the firstservice entity requests the second service entity to provide theservice, the EAC providing authentication inquiring for the firstservice entity and the second service entity according to the mechanismof authentication inquiring comprised in the negotiated authenticationmode, and generating a shared derived key for protecting thecommunication between the first service entity and the second serviceentity according to the mechanism for generating a derived key comprisedin the negotiated authentication mode; and the first service entity andthe second service entity authenticating each other according to theshared derived key and the authentication mechanism between the firstservice entity and the second service entity comprised in the negotiatedauthentication mode, and generating a session key for protecting theservice.
 2. The method according to claim 1, wherein negotiating, by thefirst service entity, an authentication mode with the EAC comprises:sending, by the first service entity, an authentication request to theEAC, wherein the authentication request carries an identity of the firstservice entity and the type of the service currently requested; and theEAC determining the second service entity for providing the serviceaccording to the type of the service currently requested, acquiringauthentication capabilities of the first service entity and the secondservice entity, and selecting the authentication mode according to theauthentication capabilities of the first service entity and the secondservice entity.
 3. The method according to claim 2, wherein, theacquiring authentication capabilities of the service entity sending theauthentication request and the service entity providing the servicecomprises: the EAC acquiring the authentication capability of theservice entity sending the authentication request from theauthentication request; and after determining the service entityproviding the service, acquiring the authentication capability of theservice entity providing the service according to the identity of theservice entity providing the service by inquiring subscription data ofthe service entity providing the service; or, the EAC acquiring theauthentication capability of the service entity sending theauthentication request according to the identity of the service entitysending the authentication request by inquiring the subscription data ofthe service entity providing the service, and after determining theservice entity providing the service, acquiring the authenticationcapability of the service entity providing the service by inquiring thesubscription data of the service entity providing the service.
 4. Themethod according to claim 1, wherein the authentication mode furthercomprises a mechanism for generating a session key between the firstservice entity and the second service entity; and generating the sessionkey for protecting the service, comprises: generating the session keyaccording to the mechanism for generating the session key between thefirst service entity and the second service entity which is comprised inthe negotiated authentication mode.
 5. The method according to claim 1,wherein, performing the mutual authentication between the EAC and thefirst service entity comprises: authenticating, by the EAC and the firstservice entity, each other; allocating, by the EAC, a temporary identityfor the first service entity; the EAC and the first service entity,respectively, acquiring a shared key material for protecting thecommunication between them, and storing the allocated temporary identitywith the acquired shared key material; performing the mutualauthentication between the EAC and the second service entity comprises:authenticating, by the EAC and the second service entity, each other;allocating, by the EAC, a temporary identity for the second serviceentity; the EAC and the second service entity, respectively, acquiring ashared key material for protecting the communication between them, andstoring the allocated temporary identity with the acquired shared keymaterial; the EAC providing authentication inquiring for the firstservice entity and the second service entity and generating a sharedderived key for protecting the communication between the first serviceentity and the second service entity, comprises: the EAC authenticatingthe authorities of the first service entity and second service entityaccording to the temporary identities of the first service entity andsecond service entity, calculating the shared derived key for protectingthe communication between the first service entity and second serviceentity according to the shared key material for protecting thecommunication between the EAC and the first service entity, thetemporary identity of the first service entity, and the temporaryidentity of the second service entity, and transferring the sharedderived key to the second service entity; the second service entityassociating the temporary identity of the first service entity, theshared derived key and the type of the service currently requested, andstoring the associated temporary identity of the first service entity,the shared derived key and the type of the service currently requested;and the first service entity calculating the shared derived keyaccording to the shared key material for protecting the communicationwith the EAC, the temporary identity of the first service entity, andthe temporary identity of the second service entity.
 6. The methodaccording to claim 5, wherein each of the shared derived key, the sharedkey material and the temporary identity has a lifetime, and the methodfurther comprises: notifying, by the EAC, the first service entityand/or second service entity corresponding to the shared key material orthe temporary identity of which the lifetime is to expire or has expiredthat a re-authentication procedure should be initiated; and/orinitiating, by the first service entity and/or second service entitycorresponding to the shared key material or the temporary identity ofwhich the lifetime is to expire or has expired, the re-authenticationprocedure to the EAC; and/or notifying, by the EAC, the first serviceentity corresponding to the shared derived key of which the lifetime isto expire or has expired that the re-authentication procedure should beinitiated; and/or notifying, by the second service entity, the firstservice entity that the re-authentication procedure should be initiatedif the lifetime of the shared derived key for protecting thecommunication between the first service entity and second serviceentity, or the lifetime of the temporary identity of the first serviceentity is to expire or has expired.
 7. A method of authenticationinquiring, applied to a system comprising a first service entityrequesting a service, a second service entity providing the service andan Entity Authentication Centre (EAC), wherein, a mutual authenticationbetween the first service entity and the EAC is performed and a mutualauthentication between the second service entity and the EAC isperformed, the EAC allocates temporary identities respectively for thefirst service entity and the second service entity and acquires theshared key materials respectively for protecting the communications withthe first service entity and the second service entity, and with theEAC, the first service entity negotiates an authentication modecomprising a mechanism of authentication inquiring and a mechanism forgenerating a derived key; the method comprising: if the first serviceentity requests the service, authenticating, by the EAC, the authoritiesof the first service entity and the second service entity according tothe mechanism of authentication inquiring comprised in the negotiatedauthentication mode; and generating, by the EAC, a shared derived keyfor protecting the communication between the first service entity andthe second service entity according to the mechanism for generating aderived key comprised in the negotiated authentication mode, wherein theshared derived key is used for authenticating each other between thefirst service entity and the second service entity.
 8. The methodaccording to claim 7, wherein if the first service entity requests theservice, authenticating, by the EAC, the authorities of the firstservice entity and the second service entity according to the mechanismof authentication inquiring comprised in the negotiated authenticationmode; and generating, by the EAC, a shared derived key for protectingthe communication between the first service entity and the secondservice entity according to the mechanism for generating a derived keycomprised in the negotiated authentication mode, comprises: the EACrespectively authenticating the authorities of the first service entityand the second service entity according to the temporary identities ofthe first service entity and the second service entity respectivelyaccording to the mechanism of authentication inquiring comprised in thenegotiated authentication mode, calculating the shared derived keyaccording to the mechanism for generating the derived key comprised inthe negotiated authentication mode, the shared key material forprotecting the communication with the first service entity, and thetemporary identity of the first service entity, and the temporaryidentity of the second service entity, and transferring the calculatedshared derived key to the second service entity; the second serviceentity storing the temporary identity of the first service entity withthe shared derived key and the type of the service currently requested;and calculating, by the first service entity, the shared derived keyaccording to the mechanism for generating the derived key comprised inthe negotiated authentication mode, the shared key material forprotecting the communication with the EAC, and the temporary identitiesof the first service entity and the second service entity.
 9. The methodaccording to claim 7, wherein if the first service entity requests theservice, authenticating, by the EAC, the authorities of the firstservice entity and the second service entity according to the mechanismof authentication inquiring comprised in the negotiated authenticationmode; and generating, by the EAC, a shared derived key for protectingthe communication between the first service entity and the secondservice entity according to the mechanism for generating a derived keycomprised in the negotiated authentication mode, comprises: providingfor the second service entity, by the first service entity, thetemporary identity of the first service entity if requesting the servicefrom the second service entity; providing for the EAC, by the secondservice entity, the temporary identity of the second service entity andthe temporary identity of the first service entity; the EAC respectivelyauthenticating the authorities of the first service entity and thesecond service entity according to the temporary identities of the firstservice entity and the second service entity respectively according tothe mechanism of authentication inquiring comprised in the negotiatedauthentication mode, calculating the shared derived key according to theshared key material for protecting the communication with the firstservice entity and the temporary identities of the first service entityand the second service entity, and transferring the calculated sharedderived key to the second service entity; storing, by the second serviceentity, the temporary identity of the first service entity with theshared derived key and the type of the service currently requested; andcalculating, by the first service entity, the shared derived keyaccording to the mechanism for generating the derived key comprised inthe negotiated authentication mode, the shared key material forprotecting the communication with the EAC, and the temporary identitiesof the first service entity and the second service entity.
 10. Themethod according to claim 7, further comprising: providing with the EAC,by the first service entity, the temporary identity of the first serviceentity and a type of the service currently requested if requesting aservice granted ticket, SGT, from the EAC; the EAC authenticating theauthority of the first service entity according to the temporaryidentity of the first service entity, acquiring the temporary identityof the second service entity according to the type of the service,authenticating the authority of the second service entity according tothe temporary identity of the second service entity, calculating theshared derived key according to the shared key material for protectingthe communication with the first service entity and the temporaryidentity of the first service entity, and the temporary identity of thesecond service entity, generating the SGT comprising the calculatedshared derived key and the temporary identities of the first serviceentity and the second service entity, and sending the generated SGT tothe first service entity; the first service entity calculating theshared derived key according to the mechanism for generating the derivedkey comprised in the negotiated authentication mode, the shared keymaterial for protecting the communication with the EAC, and thetemporary identities of the first service entity and the second serviceentity, and providing the second service entity with the SGT sent fromthe EAC if requesting the service from the second service entity; andthe second service entity acquiring the shared derived key from the SGTprovided by the first service entity, storing the temporary identity ofthe first service entity with the shared derived key and the type of theservice currently requested.
 11. The method according to claim 7,further comprising: providing for the EAC, by the first service entity,the temporary identity of the first service entity and a type of theservice currently requested if sending a service request to the EAC; theEAC authenticating the authority of the first service entity accordingto the temporary identity of the first service entity, and forwardingthe service request to the second service entity according to the typeof the service currently requested; returning, by the second serviceentity, the temporary identity of the second service entity to the EAC;the EAC authenticating the authority of the second service entityaccording to the temporary identity of the second service entity,calculating the shared derived key according to the mechanism forgenerating the derived key comprised in the negotiated authenticationmode, the shared key material for protecting the communication with thefirst service entity, and the temporary identity of the first serviceentity, and the temporary identity of the second service entity, andsending the calculated shared derived key to the second service entity;storing, by the second service entity, the temporary identity of thefirst service entity with the shared derived key and the type of theservice currently requested; and calculating, by the first serviceentity, the shared derived key according to the mechanism for generatingthe derived key comprised in the negotiated authentication mode, theshared key material for protecting the communication with the EAC, andthe temporary identities of the first service entity and the secondservice entity.
 12. The method according to claim 7, when the EACtransfers the shared derived key to the second service entity, themethod further comprising: using, by the EAC, the shared key materialfor protecting the communication with the second service entity toprotect the communication.
 13. A system for authenticating in end-to-endcommunications based on a mobile network, comprising a first serviceentity requesting a service, a second service entity providing a serviceand an Entity Authentication Centre (EAC), wherein, the first serviceentity is configured to negotiate with the EAC an authentication mode,wherein the authentication mode comprises: an authentication mechanismbetween the first service entity and the EAC, an authenticationmechanism between the second service entity and the EAC, a mechanism ofauthentication inquiring, a mechanism for generating a derived key, andan authentication mechanism between the first service entity and thesecond service entity, to perform a mutual authentication between thefirst service entity and the EAC according to the authenticationmechanism between the first service entity and the EAC comprised in thenegotiated authentication mode, to request a service from the secondservice entity, and to perform a mutual authentication between the firstservice entity and the second service entity according to the sharedderived key for protecting the communication between the first serviceentity and the second service entity according to according to theauthentication mechanism between the first service entity and the EACcomprised in the negotiated authentication mode; the second serviceentity is configured to perform a mutual authentication between thesecond service entity and the EAC according to the authenticationmechanism between the second service entity and the EAC comprised in thenegotiated authentication mode, and to perform the mutual authenticationbetween the second service entity and the first service entity accordingto the shared derived key for protecting the communication between thefirst service entity and the second service entity according to theauthentication mechanism between the first service entity and the secondservice entity comprised in the negotiated authentication mode if thefirst service entity requests the service; and the EAC is configured torespectively perform the mutual authentication between the EAC and thefirst service entity according to the authentication mechanism betweenthe first service entity and the EAC comprised in the negotiatedauthentication mode, and perform the mutual authentication between theEAC and the second service entity according to the authenticationmechanism between the second service entity and the EAC comprised in thenegotiated authentication mode, to provide an authentication inquiringfor the first service entity and the second service entity according tothe mechanism of authentication inquiring comprised in the negotiatedauthentication mode and to generate the shared derived key forprotecting the communication between the first service entity and thesecond service entity according to the mechanism for generating aderived key comprised in the negotiated authentication mode.
 14. Thesystem according to claim 13, further comprising a database for storingsubscription data of the first and second service entities; wherein, theEAC is further configured to, if negotiating the authentication mode,inquire the database according to the identities of the first serviceentity and the second service entity to acquire authenticationcapabilities of the first service entity and the second service entity,and to select the authentication mode according to the acquiredauthentication capabilities of the first service entity and the secondservice entity.
 15. The system according to claim 13, wherein, the EACis configured to, when respectively performing the mutual authenticationbetween the EAC and the first service entity and that between the EACand the second service entity, respectively, allocate temporaryidentities for the first service entity and the second service entity,acquire the shared key materials for protecting communications with thefirst service entity and the second service entity, and when providingthe authentication inquiring for the first service entity and the secondservice entity, to calculate the shared derived key for protecting thecommunication between the first service entity and the second serviceentity according to the temporary identities of the first service entityand the second service entity and the shared material key for protectingthe communication with the first service entity according to thenegotiated authentication mode, and to transfer the shared derived keyto the second service entity; the first service entity is configured to,when requesting the service, calculate the shared derived key accordingto the temporary identities of the first service entity and the secondservice entity and the shared material key for protecting thecommunication with the EAC according to the negotiated authenticationmode; and the second service entity is further configured to store thetemporary identity of the first service entity with the shared derivedkey returned by the EAC and the type of the service requested by thefirst service entity.
 16. A system of authentication inquiring,comprising a first service entity requesting a service, a second serviceentity providing the service and an Entity Authentication Centre (EAC),wherein, the first service entity is configured to negotiate with theEAC an authentication mode which comprises a mechanism of authenticationinquiring and a mechanism for generating a derived key; and the EAC isconfigured to, when the first service entity requests the service,authenticate the authorities of the first service entity and the secondservice entity according to the mechanism of authentication inquiringcomprised in the negotiated authentication mode, and to generate ashared derived key for protecting the communication between the firstservice entity and the second service entity according to the mechanismfor generating the derived key comprised in the negotiatedauthentication mode.
 17. The system according to claim 16, wherein, theEAC is configured to authenticate the authorities of the first serviceentity and the second service entity according to temporary identitiesof the first service entity and the second service entity, to calculatethe shared derived key according to the shared key material forprotecting the communication with the first service entity, thetemporary identity of the first service entity, and the temporaryidentity of the second service entity, and to transfer the calculatedshared derived key to the second service entity; the first serviceentity is configured to calculate the shared derived key according tothe shared key material for protecting the communication with the EACand the temporary identities of the first service entity and the secondservice entity; and the second service entity is configured to store thetemporary identity of the first service entity with the shared derivedkey returned by the EAC and the type of the service requested.
 18. Anauthentication centre, comprising: a first module, configured tonegotiate an authentication mode between a first service entity and theauthentication centre, wherein the authentication mode comprises: anauthentication mechanism between the first service entity and theauthentication centre, an authentication mechanism between a secondservice entity and the authentication centre, a mechanism ofauthentication inquiring, a mechanism for generating a serviced key, andan authentication mechanism between the first service entity and thesecond service entity; a second module, configured to authenticate thefirst service entity and the second service entity respectivelyaccording to the corresponding authentication mechanism comprised in theauthentication mode negotiated by the first module; and a third module,configured to, when the service entity requests the service, provideauthentication inquiring for the service entity requesting the serviceand the service entity providing the service according to the mechanismof authentication inquiring, and to calculate a shared derived key forprotecting the communication between the first service entity and thesecond service entity according to the mechanism for generating aderived key comprised in the authentication mode negotiated by the firstmodule.
 19. The authentication centre according to claim 18, wherein thefirst module comprises: a first sub-module, configured to inquiresubscription data to respectively acquire authentication capabilities ofthe service entity requesting a service and the service entity providingthe service; and a second sub-module, configured to select anauthentication mode according to the authentication capabilities of theservice entity requesting the service and the service entity providingthe service, the authentication capabilities being acquired by the firstmodule.
 20. The authentication centre according to claim 18, wherein,the second module is configured to generate shared key materials andtemporary identities for the two service entities; and the third moduleis configured to calculate the shared derived key according to theshared key materials and the temporary identities of the two serviceentities generated by the second module.